Two-cycle internal-combustion engine.



H. J. CRAWFORD. TWO-OYOLE INTERNAL GOMBUSTIN ENGINE.

APPLICATION FILED MAB. 1R, 1018.

Patented Aug. 4, 1914.

HENRY J. CEAWIFOBD, OIE' LOS ANGELES, CALIFORNIA.

TWO-CYCLE INTEENALCOMBUSTION ENGINE.

Specification of Letters Yatent.

Patented Aug. 4, 1914.

.application filed March 12, .1913. Serial No. 753,822.

i To all whom 'it may conce/m:

Be it known that I, HENRY J. CRAWFORD, a citizen of the United States,residing at Los Angeles, in the county of Los Angeles and State ofCalifornia, have invented a new and useful TwoCycle Internal-ConibustionEngine, of which the following is a specification.

This invention relates to internal combustion engines of the two cycletype and the main object of the invention is to provide improved valvemeans for controlling the supply of mixture to the engine cylinder, soas to increase the efficiency of the scavenging operation.

Another object of the invention is to provide valve means for thispurpose which will be movable rotatably with the engine shaft, so as toreduce to a minimum the number of parts required and render the valvemechanism certain and effective in its operation.

Another object of the invention is to allow more time for the intake ofmixture to crank case and cylinder.

Other objects of the invention will appeal' hereinafter.

The accompanying drawings illustrate an embodiment of the invention, andreferring thereto:

Figure 1 is a side elevation of the engine. Fig. 2 is a vertical sectionthereof. Fig. 3 is an endelevation of the engine with parts broken away.Fig. 4 is a section on line no4-m4 in Fig. 2. Fig. 5 is a section online .m5-m5 in Fig. 3.

The invention is herein shown as applied in connection with a singlecylinder engine, but it will be understood that it is equally applicablewith an engine having any number of cylinders.

1 designates the engine cylinder, 2 the crank case, 3 the engine shaftrotatably mounted in bearings 8 on said crank case, and 4 the pistonworking in said cylinder and connected by connecting rod 5 to wrist pin6v engaging in crank disks 7 upon the en gine shaft, said engine shaftbcng'divided so as to allow the connecting rod to work betweensa-idcrank disks. Said crank disks preferably occupy as much as possible ofthe space Within the crank case so as to pro vide formaximumeffectiveness of compression, said crank case being used, as acompression chamber. The crank case is shown as formed in two parts,connected by bolts 2.

Valve means are provided for controlling admission of air or mixture tothe crank case and for controlling supply of compressed mixture from thecrank case to the cylinder. For this purpose one end portion 3 of theshaft 3 is bored or made hollow as indicated at 9 to form a. passagecommunieating at its inner end wlth the interior of the crank case andclosed at its outer cud as shown at 9', a lateral port 10 extending fromsaid bore to the outside of the shaft near its outer end coperating withports 12 and 13 in a valve sleeve 11. Said, sleeve 11 operates as anadjustable valve member and is supported adjustably in position within abearing sleeve 14, formed cn or attached to the crank case. An inletpipe 15 for mixture of air and combustible communicates with the port 12in said sleeve 11, and a transfer pine or conduit 17 communicates at oneend with the port 13 in said valve sleeve and in its other end with aninlet port 19 in the engine cylinder, said inlet port being located inposition to be exposed by the piston when the latter is near the lowerend of the stroke. Directly opposite the inlet port 19 and preferablysomewhat lower down, so as to be closed somewhat earlier in the upwardstroke .is an exhaust port 20, communicating with exhaust pipe 21..Suitable means are provided for exploding the charge comprising, forexample, a spark plug 22 and a timer 23 connected in circuit in theusual manner with a magneto or battery andcoil to produce a spark at thespark plug at the proper time.

The operation` is as follows: Assuming that the parts are in positionshown in Fig. 2, and that the piston is moving upwardly, a condition ofsuction will be produced within the crank case and at this time the port10 in the shaft is in communication with the port 12 in the valve casing11, which communicates with the inlet pipe 15 for mixture, so themixture is drawn in from the carbureter through this inlet pipe, throughport 12, port 10 in theshaft and bore or longitudinal passage 9 in theshaft, to theinterior of the crank case.` As the piston reaches theupper endof its stroke the port 10 in the shaft passes the port 12closing this inlet opening and cutting oil' the supply of mixture. Inthe succeeding descent of the piston the mixture thus introduced intothe crank case is compressed, and during the whole time of compressionthc compressed mixture to pass from the crank case through the passage 9in the shaft through ports 10 and 13 and transfer pipe or conduit 17 andport 19 to the cylinder directly abor'e the piston, blowing the chargeof mixture into the cylinder and expelling the burnt gases in thecylinder through the exhaust port 20, therebyl performing the scavengingoperation and charging the cylinder with fresh mixture. Immediatelythereafter the continued ascent of the piston closes the exhaust port,allowing the charge in the cylinder to be brought up to the samepressure as in the crank case and the further upward movement of thepiston then closes the inlet port 19 and compresses the mixture abovethe piston, the cycle being completed when the piston reaches the upperend of this stroke.

What I claim is:

An internal combustion engine comprising a cylinder, a crank case, apiston Working in said cylindcr,-a shaft rotatably mounted in said crankcase and connected to be operated by the piston, said shaft having alongitudinal passage communicating with 'the crank case and providedwith a lateral port, a valve member having two ports communicating withthe lateral port in the shaft, a mixture supply means communicating'with one of said. ports, a transfer conduit communicating with the otherof said ports, said cylinder having an inlet port communicating withsaid transfer conduit to receive mixture therefrom, and lSaid `cylinderbeing provided .With an outlet port. In testimony whereof, I havehereunto set my hand at Los Angeles, California, this 5th 'day of March,1918.

HENRY J. CRAWFORD.

